Russia's foreign minister said Thursday that Moscow remains opposed to sanctions against Iran in the crisis over its nuclear program. According to the AP, Sergey Lavrov said in Warsaw that he will discuss the crisis with Iran in a meeting with his U.S., British, German, French and Chinese counterparts on Friday in London.

Imposing sanctions would be "extreme" and unconstructive, he said. "I think that until all diplomatic possibilities have been exhausted, sanctions would be extreme," Lavrov told reporters. "I think we need to do all we can to push Iran toward starting negotiations."

Lavrov expressed concern that Tehran had failed to respond positively to a package of incentives offered by the six powers to persuade Tehran to freeze its uranium enrichment program. "We are concerned that there has been no positive answer yet from Tehran," he said, according to Russia's Interfax news agency.